<template>
  <div>
    <!-- 评论列表 -->
    <div class="cmt-list" :class="isShow ? 'art-cmt-container-1' : 'art-cmt-container-2'">
      <!-- 评论的 Item 项 -->
     <van-list
     v-model="loading"
     :finished="done"
     finished-text="没有更多了"
     @load="pullUploadMore"
     offset="50"
     :immediate-check="false"
     >

        <div
      class="cmt-item"
      v-for="obj in commentList"
      :key="obj.com_id">
        <!-- 头部区域 -->
        <div class="cmt-header">
          <!-- 头部左侧 -->
          <div class="cmt-header-left">
            <img :src="obj.aut_photo" alt="" class="avatar">
            <span class="uname">{{obj.aut_name}}</span>
          </div>
          <!-- 头部右侧 -->
          <div class="cmt-header-right">
            <van-icon
            name="like"
            size="16"
            color="red"
            v-if="obj.is_liking"
            @click="likeOrDislike(obj)"/>
            <van-icon
            name="like-o"
            size="16"
            color="gray"
            v-else
            @click="likeOrDislike(obj)"/>
          </div>
        </div>
        <!-- 主体区域 -->
        <div class="cmt-body">{{obj.content}}
        </div>
        <!-- 尾部区域 -->
        <div class="cmt-footer">{{$time(obj.pubdate)}}</div>
      </div>
     </van-list>
    </div>
        <!-- 底部添加评论区域 - 1 -->
    <div class="add-cmt-box van-hairline--top" v-if="isShow">
      <van-icon name="arrow-left" size="0.48rem" @click="$router.back()" />
      <div class="ipt-cmt-div" @click="isShow = false">发表评论</div>
      <div class="icon-box">
      <van-badge :content="totalCount" max="99" >
        <van-icon name="comment-o" size="0.53333334rem" @click="scrollToView"/>
      </van-badge>
      <van-icon name="star-o" size="0.53333334rem" />
      <van-icon name="share-o" size="0.53333334rem" />
    </div>
    </div>

    <!-- 底部添加评论区域 - 2 -->
    <div class="cmt-box van-hairline--top" v-else>
      <textarea v-model.trim="content" placeholder="友善评论、理性发言、阳光心灵" v-focus @blur="onBlur"></textarea>
      <van-button type="default" @click="publishCmt" >发布</van-button>
    </div>
  </div>
</template>

<script>
import { getCommentListAPI, likeCommentAPI, disLikeCommentAPI, publishCommentAPI } from '@/api/article'
export default {
  name: 'Comment',
  data () {
    return {
      commentList: [], // 评论列表
      isShow: true, // 第一套评论区域展示与否
      totalCount: '', // 评论总条数
      content: '', // 评论内容
      loading: false, // 每一页加载状态
      done: false // 全部列表加载完成状态
    }
  },
  // 页面缓存,优化
  async activated () {
    this.getCommentList()
  },
  // 页面切换时重置所有数据状态
  deactivated () {
    this.commentList = []
    this.loading = false
    this.done = false
    this.totalCount = ''
  },
  methods: {
    // 封装函数获取评论列表
    async getCommentList () {
      const res = await getCommentListAPI({
        artId: this.$route.query.art_id,
        offset: this.lastId
      })
      const { results, total_count: total, last_id: lastId } = res.data
      if (lastId === null || results.length < 10) {
        this.done = true
        return
      }
      this.commentList = [...this.commentList, ...results]
      // 避免徽标显示0条数据
      this.totalCount = total || null
      this.lastId = lastId
      this.loading = false
    },
    // 评论点赞与否
    async likeOrDislike (obj) {
      try {
        obj.is_liking ? await disLikeCommentAPI({
          cmtId: obj.com_id
        }) : await likeCommentAPI({
          cmtId: obj.com_id
        })
        this.$toast.success(obj.is_liking ? '取消点赞' : '已点赞')
        obj.is_liking = !obj.is_liking
      } catch (error) {
        this.$toast.success(obj.is_liking ? '取消点赞失败' : '点赞失败')
      }
    },
    // 滚动列表
    scrollToView () {
      const el = document.querySelector('.like-box')
      el.scrollIntoView({
        behavior: 'smooth'
      })
    },
    // 延迟失焦(先发布)
    onBlur () {
      setTimeout(() => {
        this.isShow = true
      })
    },
    // 发布评论
    async publishCmt () {
      try {
        const res = await publishCommentAPI({
          artId: this.$route.query.art_id,
          content: this.content
        })
        this.commentList.unshift(res.data.new_obj)
        this.$toast.success('发布成功')
        this.totalCount++
        this.content = ''
      } catch (error) {
        this.$toast.success('发布失败')
      }
    },
    // 上拉加载更多
    pullUploadMore () {
      this.getCommentList()
    }
  }
}
</script>

<style scoped lang="less">
.cmt-list {
  padding: 10px;
  .cmt-item {
    padding: 15px 0;
    + .cmt-item {
      border-top: 1px solid #f8f8f8;
    }
    .cmt-header {
      display: flex;
      align-items: center;
      justify-content: space-between;
      .cmt-header-left {
        display: flex;
        align-items: center;
        .avatar {
          width: 40px;
          height: 40px;
          background-color: #f8f8f8;
          border-radius: 50%;
          margin-right: 15px;
        }
        .uname {
          font-size: 12px;
        }
      }
    }
    .cmt-body {
      font-size: 14px;
      line-height: 28px;
      text-indent: 2em;
      margin-top: 6px;
      word-break: break-all;
    }
    .cmt-footer {
      font-size: 12px;
      color: gray;
      margin-top: 10px;
    }
  }
}
/*美化 - 文章详情 - 底部的评论页面 */
// 外层容器
.art-cmt-container-1 {
  padding-bottom: 46px;
}
.art-cmt-container-2 {
  padding-bottom: 80px;
}

// 发布评论的盒子 - 1
.add-cmt-box {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  box-sizing: border-box;
  background-color: white;
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 46px;
  line-height: 46px;
  padding-left: 10px;
  .ipt-cmt-div {
    flex: 1;
    border: 1px solid #efefef;
    border-radius: 15px;
    height: 30px;
    font-size: 12px;
    line-height: 30px;
    padding-left: 15px;
    margin-left: 10px;
    background-color: #f8f8f8;
  }
  .icon-box {
    width: 40%;
    display: flex;
    justify-content: space-evenly;
    line-height: 0;
  }
}

.child {
  width: 20px;
  height: 20px;
  background: #f2f3f5;
}

// 发布评论的盒子 - 2
.cmt-box {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 80px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12px;
  padding-left: 10px;
  box-sizing: border-box;
  background-color: white;
  textarea {
    flex: 1;
    height: 66%;
    border: 1px solid #efefef;
    background-color: #f8f8f8;
    resize: none;
    border-radius: 6px;
    padding: 5px;
  }
  .van-button {
    height: 100%;
    border: none;
  }
}
</style>
